1. Field of the Invention
This invention relates to a construction disposed over a smelting furnace, e.g., an electric arc furnace, whereby air pollution due to dust and other particles is eliminated from the balance of the plant. This invention is particularly directed to an apparatus wherein means are provided for removing dust associated with a metal production or refinement operation and means are also employed for providing sound insulation. This invention is particularly directed to an enclosed smelting furnace having an upper chamber and a lower chamber disposed over said smelting furnace, said upper chamber having at least one wall having a movable door, a runway disposed partially within said upper chamber and partially out of said upper chamber, said runway carrying a charging crane. Attached to the charging crane is a second door member which is movable therewith whereby the doors can be moved in unison with one another along the path of the runway in the tapping direction whereby to insure that there is a minimum amount of air movement during the charging operation.